1. Field of the Disclosure
The invention relates to a breakaway coupling for separating two lines in the case of an excessive pull or tension between a first side and a second side of a coupling.
2. Description of the Related Art
When filling or withdrawing fluids from tanks, usually two lines are coupled together, for which purpose an actuatable coupling is used. Whereas one of the lines can be viewed as fixed in place, the other line is movable and connected to a vehicle. Motor vehicles, tanker trucks, cars of all types, ships and even aircraft are considered as vehicles. If such vehicles are set in motion while the connection of the two lines via the actuatable coupling still exists, it may happen that the line connection is torn apart. In order to avoid this, a breakaway coupling is disposed in the connection line run, this breakaway coupling responding when there is excessive pull or tension, and the two lines that are coupled are separated from one another. The breakaway coupling has automatically closing fluid barriers that respond in the case of separation of the lines and block the respective line. In this way, unwanted movements of the vehicle are prevented from leading to an environmentally damaging emergency situation.
Deep-cooled media, for example, liquefied natural gas, are considered as fluids being transported and must be delivered via lines that are coupled together. For these coupled lines, in each case a breakaway coupling is required that withstands the conditions of deep-cooled media.
An emergency disconnect safety coupling is shown in DE 91 14 005 U1. There are two coupling halves that are held together via retaining ring segments, which engage from outside into annular grooves of the connection edges of the coupling halves and which in turn are comprised of a retaining element. A seal that presses the coupling halves together can be disposed between these halves, and thus the coupling parts can be easily disconnected when the radial load is removed. Such a press seal is not very effective in the case of very low temperature.
A tubular connection with collars that lie opposite one another on the end face is known from DE 198 14 559 A1, in which the collars together with an intermediate-lying seal are clamped against one another by means of a detachable clamping device, with the formation of a fluid-tight connection. An O-ring or a flat gasket are named as seals. Such seals are not very effective at very low temperatures.